/*
 * Fowler / Noll / Vo Hash (FNV Hash)
 * http://www.isthe.com/chongo/tech/comp/fnv/
 *
 * This is an implementation of the algorithms posted above.
 * This file is placed in the public domain by Peter Wemm.
 */
#ifndef _SYS_FNV_HASH_H_
#define	_SYS_FNV_HASH_H_

typedef uint32_t Fnv32_t;
typedef uint64_t Fnv64_t;

#define	FNV1_32_INIT ((Fnv32_t)33554467UL)
#define	FNV1_64_INIT ((Fnv64_t)0xcbf29ce484222325ULL)

#define	FNV_32_PRIME ((Fnv32_t)0x01000193UL)
#define	FNV_64_PRIME ((Fnv64_t)0x100000001b3ULL)

static __inline Fnv32_t
fnv_32_buf(const void *buf, size_t len, Fnv32_t hval)
{
	const uint8_t *s = (const uint8_t *)buf;

	while (len-- != 0) {
		hval *= FNV_32_PRIME;
		hval ^= *s++;
	}
	return (hval);
}

static __inline Fnv32_t
fnv_32_str(const char *str, Fnv32_t hval)
{
	const uint8_t *s = (const uint8_t *)str;
	Fnv32_t c;

	while ((c = *s++) != 0) {
		hval *= FNV_32_PRIME;
		hval ^= c;
	}
	return (hval);
}

static __inline Fnv64_t
fnv_64_buf(const void *buf, size_t len, Fnv64_t hval)
{
	const uint8_t *s = (const uint8_t *)buf;

	while (len-- != 0) {
		hval *= FNV_64_PRIME;
		hval ^= *s++;
	}
	return (hval);
}

static __inline Fnv64_t
fnv_64_str(const char *str, Fnv64_t hval)
{
	const uint8_t *s = (const uint8_t *)str;
	uint32_t c;

	while ((c = *s++) != 0) {
		hval *= FNV_64_PRIME;
		hval ^= c;
	}
	return (hval);
}
#endif /* _SYS_FNV_HASH_H_ */
